1. Technical Field
The present invention relates to an electronic drawing system with a flexible circuit board based force sensor included in an electronic pen for sensing pressures applied against the pen tip of the electronic pen.
2. Description of Related Art
FIGS. 1A-1B show a prior art.
FIG. 1A shows a traditional electronic drawing system, including a transparent coordinate panel 11 and an underlaid display 12. An electronic pen 10 is electrically coupled to the coordinate panel 11 and the display 12. When the electric pen 10 draws onto a surface of the coordinate panel 11, the display 12 displays stokes the pen has drawn.
FIG. 1B shows a section view according to line AA′ in FIG. 1A. FIG. 1B shows a coordinate panel 11 for detecting X-Y coordinates of the position of a point the pen touches. A display 12 is configured on bottom of the coordinate panel 11.
FIG. 2 shows a prior art electronic pen.
FIG. 2 shows a pen tip 13, optical sensor 14 for sensing pressure applied against the pen tip 13. A printed circuit board 15 for processing the signal information and transmits to a display, a batter 16 provides the energy for powering the pen.